The present invention relates to a braille printing plate.
It is known to use a braille writing instrument or braillewriter for braille printing. Additionally, the present inventor has previously developed a braille printing plate which can print braille without using a braille writing instrument or braillewriter, and can store the braille for a long time as a master plate, as is disclosed in European Patent Publication No. 169959.
In the inventor's above prior invention, braille is printed with use of a punched plate made of hard plastic or similar material, having all rows punched with dot holes, six of which correspond to one braille letter. (See the numeral 10 shown in FIG. 1 of the European Patent Publication No. 169959.) On one surface of the punched plate is pasted a ball retaining sheet such as a vinyl chloride sheet and on the other surface is pasted a dot hole sheet. The brailleforming dot holes are punched in the dot hole sheet with a stylus or braillewriter so as to project the ball retaining sheet outwardly, balls are then loaded in recesses formed in the ball retaining sheet, and thereafter a sheet is pasted on the dot hole sheet to provide a stable support for the balls. Thus, braille letters are formed and a master printing plate is obtained.
The above prior art using balls to form letters on the master printing plate is advantageous in that the braille letters will not be defaced even if printing is repeated, the printed braille letters are easy to read, two to three sheets can be clearly printed at one time, and the balls can be taken out after printing so that the balls and punched plate are available for repeated use.
Braillewriters differ somewhat from each other in the braille size and/or the line spacing, according to the manufacturer. If the master plate is to be made using the braillewriter, the punched plate is required to register with the braillewriter in the braille spacing. The prior art proposed by the inventor is suitable for producing the master plate with a stylus, but is faced with the aforementioned problem when using the braillewriter.
Recently, there has been developed a computer-aided braille writing machine, in which ordinary letters are input and computerized so as to print braille letters. Advantageously, a person without knowledge of braille can operate this machine. Further, data can be recorded in floppy disk and duplicated easily. The convenience of this machine is incomparable with the conventional braillewriter, but this braille writing machine and associated braille printer are so expensive that it is actually difficult for even a braille library to purchase them.